An unrelenting downpour has battered low-lying parts of the city since the early hours of Tuesday, with some areas receiving almost 12 inches of rain. Weather forecasts suggested that the rain will continue over the next 48 hours before it begins to decrease.

Vehicles gingerly made their way through waterlogged roadways as residents sloshed through flooded streets – navigating waist-high water in some areas – after being sent home early from offices and schools.

Indian Prime Minister Narendra Modi urged people in affected areas to be safe and "take all essential precautions in the wake of the heavy rain," in a series of posts on Twitter.

The Indian Navy has put flood rescue teams on standby at multiple locations across Mumbai in anticipation of worsening conditions.

Thousands of commuters faced difficult journeys home with the heavy monsoon rains leaving some stranded or facing delays at train stations. So far, no casualties have been reported.

In the Parel neighborhood of Mumbai, Piyush Jain posted a video on Twitter showing inflatable dinghies being used to ferry people across stricken roads.

Domestic airline operators – including Vistara and Jet Airways – tweeted flight diversions and cancellations to the coastal city of nearly 20 million people.

"There are around 25 locations where there's intense waterlogging and they've had to divert traffic," Devendra Fadnavis, chief minister of Maharashtra state told reporters. "We're advising offices to give their employees the rest of the day off and leave as soon as they can."

India's National Disaster Management Authority has been updating its social media feeds with safety advisories and helpline phone numbers, while Mumbai police have cautioned people to stay inside their homes and to abandon vehicles stuck in water amid the deluge.

Its official account also warned people of a high tide which was expected to hit the city in the late afternoon.

"It has been raining so heavily that water from manholes is spilling onto the roads," local resident Aman Patel told Reuters. "It seems as if no measures have been taken. It has been raining so heavily that people are having a tough time."

Local media reported that the downpour could become the worst in Mumbai since 2005, when hundreds were killed after the city received 39 inches of rain in 24 hours, according to the Regional Meteorological Centre.

But officials downplayed the comparison. Rajiv Nivatkar, director of the Disaster Management Unit in Mumbai, told CNN: "It is not a flood-like situation because no one needs to be rescued."